The info in AC43.13 is great - thanks. So vakuable that I eventually downloaded all of the chapters while the going was good.

Does anyone know if ANC-18, Design of Wood Aircraft Structures is available in similar format.

My particular interest at this time is the proper design of metal wing attchment fittings (wood spars). The fittings aill be located at half-span in laminated, tapering spar caps - maybe wing joiners is a better description?

I initially I thought that I would cover it with some over-design, but recent information indicates that I need to learn a lot more about hole spacing (and size) in wood. Also that the "yield" in the metal (strap) and the wood should be in sync, so a WAF that varies in modulus over its length.

My drawings will be subjected to professionl scrutiny before I cut any wood, but I would like to get it as close as I can before then.